01 - Preheat the oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a large bowl, whisk together melted butter, sugar, and ube halaya until smooth and fully incorporated.
03 - Add eggs and vanilla extract to the ube mixture, whisking until the batter is uniform and creamy.
04 - In a separate bowl, sift together flour, salt, and baking powder to ensure even distribution.
05 - Gently fold the dry ingredients into the ube mixture, mixing just until combined. Avoid overmixing to prevent tough brownies.
06 - Melt the chocolate with 2 tablespoons of butter in a microwave-safe bowl, heating in 30-second intervals and stirring until smooth.
07 - Spread the ube brownie batter evenly in the prepared pan. Dollop the melted chocolate mixture on top in several spots, then use a skewer or knife to create a marbled swirl pattern.
08 - Bake for 32–36 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs attached.
09 - Allow the brownies to cool completely in the pan before lifting out using the parchment overhang and slicing into squares.